Power section is 4el34's, but you can also use 4 kt66's for the sweet tone that they give up as well.  and the preamp uses 3 12ax7's.  Solid state rectification keeps this amp tight, even when wound up.
Built with the same attention to detail, and high quality of all of our amps. Custom wound Heyboer OT, hand assembled and wired with Mil Spec PEC pots, ARS filter caps, "Dijon"  and mallory and sozo coupling caps, NOS carbon comp resistors in all critical locations.  Chassis are welded for extra support and durability, and switches are all  heavy duty units for long troublefree service.  I am constantly testing preamp tubes for the best possible combination of tubes.
I have also been testing the use of KT66's in this amp, and its amazing.  All amps are now set up with the ability to adjust for KT66's, to give you that early Page,Clapton, etc type tone.
All amps come standard with:
Heyboer power and output transformers and choke
PEC mil spec pots
Winged C or Mullard RI  matched el34 power tubes.
A mix of Mullard, JJ, EI, or Tungsol preamp tubes.
NOS carbon comp resistors on plates and cathodes
"Dijon" , Sozo, and mallory coupling caps
ARS and Sprague high quality filter caps
Handwired with silver core teflon jacketed wire.
External bias jacks, with top mounted 10 turn bias pot for easy,  precise biasing.